In a typical data center environment, a server rack is positioned between a hot aisle and a cold aisle to achieve a higher cooling efficiency. In the typical configuration, the ambient air temperature is cool at the front of the rack and is hot at the rear of the rack, with the air temperature between the cold and hot aisles showing a gradient between the two, but generally considered to be a “warm” zone.
For rack-mounted servers with cold air intakes on the front of the rack, the typical arrangement is optimal for providing cool air to the server from the cold aisle and for exhausting heated air from the server to the hot aisle.
However, because of design and other layout limitations, many rack switches are configured to be mounted at the rear of the rack and to use side inlet air for cooling. Such rack switches also exhaust air toward the front of the rack. This typical data center environment causes at least two problems regarding such rack switches. First, the air used for cooling the rack switch is taken from the warm zone, which is not optimal for cooling the rack switch. And second, the heated exhaust air created by the rack switch is exhausted toward the front of the rack—into the cold aisle—which is not optimal for cooling the rack-mounted servers because it mingles with the cold aisle air and increases its temperature. And when servers operate at higher temperatures they consume more power because they increase fan speeds in response to increased operating temperature.
Some solutions may: provide cooling air to switches from the hot aisle or warm zone and exhaust hot air to the cold aisle (as described above); or use two rack units (2 U) of space. The first solution is undesirable for the reasons just discussed. The 2 U solution is undesirable because it uses twice the rack space—two slots of the rack. In the 2 U solution the first slot is taken by the switch and the second slot is taken by a duck that re-directs heated exhaust air over the top of the rack switch and toward the hot aisle at the rear of the rack.
Therefore, the need exists for a solution that doesn't require a second rack slot, that provides air from the cold aisle for cooling the rack switch, and that diverts the rack switch's heated exhaust air away from the cold aisle.